Plant Science for Global Challenges

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Month: January 2017

By Baraka Rateng’

Struggling East African dairy farmers could benefit from new varieties of high-quality, drought-resistant forage grass known as Brachiaria that boosts milk production by 40 per cent, a report says.

The forage grass could enable farmers to increase their incomes, according to experts at the Colombia-headquartered International Center for Tropical Agriculture (CIAT) – a CGIAR Research Center.

Steven Prager, a co-author of the report — which was published last month — and a senior scientist in integrated modelling at the CIAT, says the report was based on many years of forage research in Latin America and the Caribbean, and recent field trials in Kenya and Rwanda from 2011 to 2016.

According to Prager, the study demonstrates the high potential for improved forages in East Africa and high payoff for investment in improved forages.

“The results are based on multiple scenarios of an economic surplus model with inputs derived from a combination of databases, feedback from subject matter experts and a literature review,” he explains, adding that the economic analysis was carried out at CIAT headquarters with the support of tropical forage experts in East Africa.

“The objective of this study was to understand the potential payoff for investment in action to improve dissemination and use of improved forages,” Prager tells SciDev.Net.

“The objective of this study was to understand the potential payoff for investment in action to improve dissemination and use of improved forages.”

Steven Prager, International Center for Tropical Agriculture (CIAT)

One of the big unknowns in the development and implementation of agricultural technology, according to Prager, is how many potential users are required to make it worthwhile to invest in the development and designation of different technologies.

Solomon Mwendia, a co-author of the report and forage agronomist at CIAT, Kenya, says the Brachiaria grass is climate-friendly and has high crude protein and less fiber, which leads to better use and digestion by cattle, in turn leading to less methane gas produced for each unit of livestock product such as milk or meat. Methane is one of the gases associated with global warming.

“This grass is relatively drought-tolerant compared to the Napier or elephant grass commonly used in East Africa. In addition, the grass can easily be conserved as hay for utilisation during forages scarcity or for sale,” Mwendia adds.

Smallholder dairy farming is important in East Africa for household nutrition and income. In Kenya, for instance, Mwendia says that milk production increased by 150 per cent between 2004 and 2012, from 197.3 million litres to 497.9 million litres.

The grass is native to Africa, according to Mwendia. It can grow in areas with up to 3,000 millimetres of rainfall and also withstand dry seasons of three to six months during which the leaf may remain green while other tropical species die. These conditions exist in other regions outside eastern Africa such as in Democratic Republic of Congo, Malawi, Zambia and Zimbabwe.

Sita Ghimire, a senior scientist at the Biosciences eastern and central Africa (BecA) Hub, who leads a research programme that focuses on Brachiaria, says 40 per cent increase in milk production is achievable in East Africa after feeding livestock with Brachiaria.

“Forage has been always a major challenge in livestock production in East Africa. It is mainly because of declining pastureland, frequent and prolonged drought and not many farmers conserve forage for dry season,” Ghimire says.

The major challenges for adoption of Brachiaria technology in East Africa are limited availability of seeds or vegetative materials, lack of standardised agronomic practices for different production environments and lack of varieties that are well adapted to East African environment, Ghimire explains, citing other challenges such as pest and diseases, and low funding forage research and development.

Edith, you have put a huge amount of work into uncovering the history of plant physiology research in Argentina. Why did you decide to do it and how did you undertake this challenge?

The current president of the SAFV, Pedro Sansberro, asked Alberto Golberg and myself if we would be willing to document the history of the society. Unaware of the tremendous task ahead, we agreed.

The information was scattered, so the first thing we did was try to collect as many SAFV conference books as possible. Sending requests through the SAFV mailing did not work, so it was essentially through personal contacts that we were able to put together the whole collection of conference books. It is now deposited in the library of CIAP (Centro de Investigaciones Agropecuarias – contact: [email protected]). People also sent the minutes of past meetings and pictures.

Initially we were only going to analyze the conference books and interview some plant scientists that were among the first disciples of the “founding fathers” of Argentinian experimental plant biology, but as we worked, our book grew and diversified.

What was the most interesting thing you discovered while writing the book?

It’s hard to narrow down which discovery was most exciting!

Victorio Trippi, one of the disciples of the “founding fathers”, told us that many researchers initially published in the journal Phyton, which was founded in Argentina in 1951. Our inspection of the archives of this publication yielded a lot of valuable information, and was an enlightening experience. We traced great names in Argentine plant science to the very beginning of their careers, looking at their topics of interest, how they moved from one job to another, and who their co-authors were. Even earlier than this though, we managed to trace the first mention of plant hormones in Argentina to a paper written by Guillermo Covas in 1939.

Writing the book was rewarding too, because we realized that plant physiology research has steadily grown in Argentina, judging by the participation in the conferences and the amount of research groups all over the country. It was very good to reveal the significant contributions that Argentine experimental plant science has made to many topics, such as photobiology, crop ecophysiology, germination physiology, senescence, mineral nutrition and carbohydrate metabolism, among others.

Why did you decide to include essays from the many groups researching plant physiology in Argentina?

We included them to reflect how much plant physiology has grown and diversified in Argentina. In the book we also invite those that did not have a chance to join this edition to contribute to a future one.

What words of wisdom did the researchers who were interviewed want to share with early career researchers for the future?

Most of them emphasized the need for team work, with people from different background joining forces to tackle a specific problem. The SAFV, they point out, has provided a friendly environment that has promoted collaboration and exchange of ideas among its members, and they hope this spirit will persist. They are moderately optimistic about the future, underscoring the need for new research paradigms both in the public and private sectors.

Carlos Ballaré underscored the human aspect of the history of the SAFV in his description of your book, printed on the cover. Could you elaborate on this?

Carlos meant that the book includes personal accounts from the people that have devoted their professional lives to plant physiology and ecophysiology, anecdotes of how the research groups developed and grew, and tales of how researchers replaced the lack of equipment with clever ideas. He highlights that the book has an emphasis on human endeavor, rather than being just a review of numbers, places, and dates.

Beyond the analysis of numbers and growth, the book reveals how early researchers worked on problems that largely sprang from their environment, attempting to understand the causes of issues that had an impact on crop productivity. Thus, those in Tucumán initially worked on sugar cane, those in Mendoza researched grapevines, and the focus in Buenos Aires was potatoes. As groups grew and diversified, this initial link was often blurred; young researchers joining ongoing work never realized what the initial question had been.

In a country where agricultural products or their derivatives still make a significant contribution to GDP, it is sensible to resume the link to local agricultural problems. For this task, it will be essential to adopt a systemic collaborative approach.

By Marie Haga , Ann Tutwiler

The efforts of many organisations mean that most of us understand the importance of conserving the biodiversity of wild animals and their habitats. But few of us think about food in the same way we think about pandas, even though the issues are much the same.

And as with pandas and other wild animals, conservation of agricultural biodiversity can and must be done both in the laboratory and in the field.

From pandas to seeds

If you had a choice, would you rather see a panda in a zoo, or in the bamboo forests of southern China?

For most of us, seeing wild and endangered animals in their own habitat and watching how they behave, adapt and survive in their natural surroundings would be the preferred choice. But, the role of zoos in conserving wild and endangered animals is equally important.

Many zoos are home to breeding programmes. These can help re-introduce animals into wild areas from which they have disappeared, and maintain the genetic diversity of small populations of threatened species. Zoos that are well-run carry out vital conservation research and can increase public support for conservation. And the only chance that most of us (and our kids) will have to see a panda is in a zoo.

Much in the same way, and for several decades now, dedicated researchers around the world have invested a great deal of effort in collecting and storing the seeds of different varieties of crops in genebanks, for what’s called ex situ conservation. Their collective work has created a precious global collection of over seven million seed, tissue, and other samples in many global and national genebanks.

“The problem is that systems of in situ and ex situ conservation have been largely disconnected for some time. Some conservationists even see them as antagonistic.

And while devotees of one side argue with the other, the diversity that underpins the food we eat is lost both in genebanks and in farmers’ fields.”

Marie Haga and Ann Tutwiler

At the same time, some concerns that apply to zoos — that they cannot maintain the evolutionary dynamics which allow ‘wild’ animals to evolve and adapt, for example — also apply to seed banks.

Researchers are increasingly recognising that in situ conservation is also important: maintaining crop and livestock diversity in farmers’ fields and farms, gardens, orchards, and the natural landscapes in which these are embedded.

A call for collaboration

Ex situ and in situ conservation each has their benefits.

It is relatively cheap to maintain crop diversity in a genebank, where it is safe from the vagaries of changing climates, and is readily accessible for research and breeding. But crop diversity stored in genebank is less accessible to farmers, and is not exposed to changing environments — which means it does not evolve and adapt.

On the other hand, crop diversity in farmers’ fields and under other in situ conditions, continues to evolve and adapt as a result of natural and human selections. As it evolves and adapts, this genetic diversity contributes directly to the resilience and sustainability of agricultural systems, as well as to farmers’ livelihoods and to their empowerment. But there’s a downside: it is more difficult for breeders to use in their crop improvement programmes.

This shouldn’t be about choosing one over the other — the world needs both conservation systems, with good communication channels and knowledge transfer between them. This will help to properly conserve the genepools of crops and make them available for use into the future, for food and nutritional security.

The problem is that systems of in situ and ex situ conservation have been largely disconnected for some time. Some conservationists even see them as antagonistic.

And while devotees of one side argue with the other, the diversity that underpins the food we eat is lost both in genebanks and in farmers’ fields.

Crop diversity in farmer’s fields continues to decline in many parts of the world, often driven by market forces beyond the control of farmers’ themselves. Diversity is also lost from genebanks — a shortage of funding and staff means collections are often poorly maintained.

But if we stop looking at these two forms of conservation as antagonistic but rather as complementary, attention can be focused on what matters most: how best to safeguard this diversity for the future.

First steps

The First International Agrobiodiversity Conference is an opportunity to begin anew. That’s why practitioners in all these fields, from all over the world, both industrialized and developing, and from both the formal and informal sector, are coming together in New Delhi, India this week.

This congress gives conservation and agro-biodiversity experts and policy makers the opportunity to start mapping out a future that breaks down barriers between the two approaches, integrating them to ensure global food and nutritional security.

Most importantly, this means helping politicians and the public understand that conserving the diversity of our food is just as important as conserving the diversity of wild animals.

The congress is a first step in the right direction.

Marie Haga is executive director of The Crop Trust, and Ann Tutwiler is director general of Bioversity International. Haga can be contacted on Twitter at@CropTrust, and Tutwiler at @AnnTutwiler.

January

The year began with the publication of the fascinating eelgrass (Zostera marina) genome by an international team of researchers. This marine monocot descended from land-dwelling ancestors, but went through a dramatic adaptation to life in the ocean, in what the lead author Professor Jeanine Olsen described as, “arguably the most extreme adaptation a terrestrial… species can undergo”.

One of the most interesting revelations was that eelgrass cannot make stomatal pores because it has completely lost the genes responsible for regulating their development. It also ditched genes involved in perceiving UV light, which does not penetrate well through its deep water habitat.

February

Plants are known to form new organs throughout their lifecycle, but it was not previously clear how they organized their cell development to form the right shapes. In February, researchers in Germany used an exciting new type of high-resolution fluorescence microscope to observe every individual cell in a developing lateral root, following the complex arrangement of their cell division over time.

Using this new four-dimensional cell lineage map of lateral root development in combination with computer modelling, the team revealed that, while the contribution of each cell is not pre-determined, the cells self-organize to regulate the overall development of the root in a predictable manner.

Watch the mesmerizing cell division in lateral root development in the video below, which accompanied the paper:

March

In March, a Spanish team of researchers revealed how the anti-wilting molecular machinery involved in preserving cell turgor assembles in response to drought. They found that a family of small proteins, the CARs, act in clusters to guide proteins to the cell membrane, in what author Dr. Pedro Luis Rodriguez described as “a kind of landing strip, acting as molecular antennas that call out to other proteins as and when necessary to orchestrate the required cellular response”.

April

In April, we received an amazing insight into the ‘decision-making ability’ of plants when a Swiss team discovered that plants can punish mutualist fungi that try to cheat them. In a clever experiment, the researchers provided a plant with two mutualistic partners; a ‘generous’ fungus that provides the plant with a lot of phosphates in return for carbohydrates, and a ‘meaner’ fungus that attempts to reduce the amount of phosphate it ‘pays’. They revealed that the plants can starve the meaner fungus, providing fewer carbohydrates until it pays its phosphate bill.

Author Professor Andres Wiemskenexplains: “The plant exploits the competitive situation of the two fungi in a targeted manner, triggering what is essentially a market-based process determined by cost and performance”.

May

The transition of ancient plants from water onto land was one of the most important events in our planet’s evolution, but required a massive change in plant biology. Suddenly plants risked drying out, so had to develop new ways to survive drought.

In May, an international team discovered a key gene in moss (Physcomitrella patens) that allows it to tolerate dehydration. This gene, ANR, was an ancient adaptation of an algal gene that allowed the early plants to respond to the drought-signaling hormone ABA. Its evolution is still a mystery, though, as author Dr. Sean Stevensonexplains: “What’s interesting is that aquatic algae can’t respond to ABA: the next challenge is to discover how this hormone signaling process arose.”

June

Sometimes revisiting old ideas can pay off, as a US team revealed in June. In 1930, Ernst Münch hypothesized that transport through the phloem sieve tubes in the plant vascular tissue is driven by pressure gradients, but no-one really knew how this would account for the massive pressure required to move nutrients through something as large as a tree.

Professor Michael Knoblauch and colleagues spent decades devising new methods to investigate pressures and flow within phloem without disrupting the system. He eventually developed a suite of techniques, including a picogauge with the help of his son, Jan, to measure tiny pressure differences in the plants. They found that plants can alter the shape of their phloem vessels to change the pressure within them, allowing them to transport sugars over varying distances, which provided strong support for Münch flow.

BLOG: We featured similar work (including an amazing video of the wound response in sieve tubes) by Knoblauch’s collaborator, Dr. Winfried Peters, on the blog – read it here!

July

Preserved remains of rope, seeds, reeds and pellets (left), and a desiccated barley grain (right) found at Yoram Cave in the Judean Desert. Credit: Uri Davidovich and Ehud Weiss.

In July, an international and highly multidisciplinary team published the genome of 6,000-year-old barley grains excavated from a cave in Israel, the oldest plant genome reconstructed to date. The grains were visually and genetically very similar to modern barley, showing that this crop was domesticated very early on in our agricultural history. With more analysis ongoing, author Dr. Verena Schünemannpredicts that “DNA-analysis of archaeological remains of prehistoric plants will provide us with novel insights into the origin, domestication and spread of crop plants”.

BLOG: We interviewed Dr. Nils Stein about this fascinating work on the blog – click here to read more!

August

Another exciting cereal paper was published in August, when an Australian team revealed that C4 photosynthesis occurs in wheat seeds. Like many important crops, wheat leaves perform C3 photosynthesis, which is a less efficient process, so many researchers are attempting to engineer the complex C4 photosynthesis pathway into C3 crops.

This discovery was completely unexpected, as throughout its evolution wheat has been a C3 plant. Author Professor Robert Henrysuggested: “One theory is that as [atmospheric] carbon dioxide began to decline, [wheat’s] seeds evolved a C4 pathway to capture more sunlight to convert to energy.”

September

September marked an historic event. Professor Stefan Jansson cooked up the world’s first CRISPR meal, tagliatelle with CRISPRy fried vegetables (genome-edited cabbage). Jansson has paved the way for CRISPR in Europe; while the EU is yet to make a decision about how CRISPR-edited plants will be regulated, Jansson successfully convinced the Swedish Board of Agriculture to rule that plants edited in a manner that could have been achieved by traditional breeding (i.e. the deletion or minor mutation of a gene, but not the insertion of a gene from another species) cannot be treated as a GMO.

October

Phytochromes help plants detect day length by sensing differences in red and far-red light, but a UK-Germany research collaboration revealed that these receptors switch roles at night to become thermometers, helping plants to respond to seasonal changes in temperature.

Dr Philip Wiggeexplains: “Just as mercury rises in a thermometer, the rate at which phytochromes revert to their inactive state during the night is a direct measure of temperature. The lower the temperature, the slower phytochromes revert to inactivity, so the molecules spend more time in their active, growth-suppressing state. This is why plants are slower to grow in winter”.

November

A fossil ginkgo (Ginkgo biloba) leaf with its modern counterpart. Image credit: Gigascience.

In November, a Chinese team published the genome of Ginkgo biloba¸ the oldest extant tree species. Its large (10.6 Gb) genome has previously impeded our understanding of this living fossil, but researchers will now be able to investigate its ~42,000 genes to understand its interesting characteristics, such as resistance to stress and dioecious reproduction, and how it remained almost unchanged in the 270 million years it has existed.

Author Professor Yunpeng Zhaosaid, “Such a genome fills a major phylogenetic gap of land plants, and provides key genetic resources to address evolutionary questions [such as the] phylogenetic relationships of gymnosperm lineages, [and the] evolution of genome and genes in land plants”.

December

The year ended with another fascinating discovery from a Danish team, who used fluorescent tags and microscopy to confirm the existence of metabolons, clusters of metabolic enzymes that have never been detected in cells before. These metabolons can assemble rapidly in response to a stimulus, working as a metabolic production line to efficiently produce the required compounds. Scientists have been looking for metabolons for 40 years, and this discovery could be crucial for improving our ability to harness the production power of plants.